Device for controlling belt alignment



May 8, 1956 D. GLUCK DEVICE FOR CONTROLLING BELT ALIGNMENT Filed NOV. 18, 1953 Dal/1a G/zzalc T Z H5 .ITTFE TJZUT v a 1 2,744,363 DEVICE FOR CONTROLLING BELT ALIGNMENT.

David Gluck, Toronto, Ontario, Canada, assignor to Houdaille Industries, Inc., Detroit, Mich., a corporation of Michigan 7 Application November 18, 1953, Serial No. 392,928

s Claims. (c1. 51-439 This invention relates to a belt control device or the like, and is particularly concerned with a belt control system for laterally oscillating the belt of a polishing machine.

' In polishing machines, it is very desirable to have a belt control system which is reliable inoperation. A

failure in the belt control results in a broken belt and represents a considerable loss in time and money.

It is therefore an important object of the present invention to provide a belt control system which is capable 0 2.5

It is a further object of the present invention to prorelatively trouble-free operation.

vide a belt control systemwhi'ch requires less maintenance time than existing systems. v I It is another object of the present invention to provide a belt control systemhaving aminimum of moving parts. p

It is still another object of the present invention to pro- 2,744,353 l atented May 8, 1956 .terial 13 in'theconventional manner by means of rollers 14, 15 and '16. For polishing thesurface of the material 13 as it 'passes between the rollersvl'7 and 18, a polishing belt-19 is trained around the upper roller 18 for-polish-in'g-contact with the'surface of the material 13; The belt*'19 is disposed in a closed loop and is trained around an idler roll- Maud atracking roll 21 which-is adapted to oscillate about a central vertical axis to shift the position of the belt 19 laterally relative to the sheet material 13. ,The' details of construction ofthe means for feeding the sheet 13 and for mounting the polishing bel't19 for lateral oscillationrelative thereto are all conventional and have been indicated only diagrammatically.

The-tracking roll 21 is illustrated as being mounted by means -of,- ayoke including upstanding journal members "22 and -23 *journalling opposite ends ofthe tracking roll shaft 25,,and secured to a base 24 which is suitably mounted by the frame work for oscillation on a vertical axis. Theyertical axis of oscillation may coincide with the aX-is:of the recess 26 indicated in Figures 1 and 2.

For oscillating the tracking roll 21, a double acting cylinder. 30 has, been diagrammatically illustrated as being vide a novel belt control device'for cooperation'with a belt to provide pressure variations-indicative of the po-' sition of the belt relative to the device.

It is anotherand further object and feature of the present invention to provide abelt control device constructed to maintain the'belt in obstructing relation to a pressure discharge orifice. 1

It is yet a further object of the present invention to pro vide a belt control device wherein the belt is maintained in obstructive relation to a pressure discharge orifice in spite of any accidental lateral travel of the belt edge bev yond the orifice.

Other .objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying sheet ofdrawings, in which:

On the drawings:

Figure 1 is a diagrammatic front elevational view of a polishing machine incorporating a belt controlsy'stem according to the present invention;

Figure 2 is a fragmentary diagrammatic plan view of a portion of the structure of Figure 1;

Figure 3 is a fragmentary diagrammatic left side elevational viewof the structure of Figure l and indicating diagrammatically the pneumatic and electric control circuit of the system of the present invention;

Figure 4- is a diagrammatic side elevational view of an air eye block constructed in accordance with the present invention; and

Figure 5 is a diagrammatic top plan view of the structure of Figure 4 and illustrating the manner in which the edge of'the belt cooperates with the air eye block.

As shown on the drawings: 1

The belt control system of the present invention is parfmounted by means of a lug 33 from a platform 31 secured with the framework 11 of the machine. The double acting cylinder is indicated as havinga piston arm 35 connected with the journal member 22 for oscillating the tracking roll about its central vertical axisfas best seen in Figure 2. p i I For controlling the oscillation of the tracking roll 21, an air eye block 38 is provided for producing a change in pressure in response to a change in the position of the belt 19 relative thereto. In particular, .the air eye block SS-constitutes an air' discharge member having a discharge orifice 39 adjacent one edge of the belt 19 and arranged to be obstructed by the belt. The 'belt control system is designed so that obstruction'of the orifice 39 of themember-38 causes oscillation of the tracking roll in a direction to-move the belt 19 away from the'orifi-ce .39. The system is further constructed so that when the belt moves out of obstructing relation to theorifice 39, the control system is actuated to oscillate the tracking roll 21 insthe opposite direction and to begin movement of g the belt in the opposite lateral direction toward obstructtion.

ing relation to the orifice 39. In this manner, the belt 19 is continuously oscillated during the polishing opera- As-indicated in Figure 3, pressure is supplied to the chamber within the block 38 from the air supply conduit 40through a'filter 41, an air regulator 32 set toap proximately ten pounds per square inch, a safety valve ,43,-set,-at fifteen pounds per square inch to protectthe .mercoid switch 57, and an air gauge 44. Air at a predetermined pressure is thus applied to the central chamber of the member 38 by means of the conduit 45 for ticularly adapted for controlling lateral oscillation of a discharge through the orifice 39. A further air conduit 52 is in communication with the chamber of the member 38 and transmits the pressure thereof through an air pressuregauge 55 to a mercoid switch 57. The mercoid switch may'have a range from zero to fifteen pounds 60,

per square inch and may be responsive to a minimum ,pressure differential of one-half pound per square inch.

switch 57 due to obstruction of the orifice 39 by the belt will cause actuation of the solenoid valve 66 by means of electrical conductors 58 and 59 to connect air pressure from the line 40'to the line 62. 'As seen in Figure i, this causes pressure to be applied to theleft end of cylinder 30 to extend the piston 35 and move the belt 39 rearwardly away from the discharge orifice 39. When the discharge orifice 39 is unobstructed, pressure in the line 52 decreases causing the mercoid switch 57 to again be actuated (for example, to open a pair of electric contacts in line 58) to shift solenoid valve 60 to supply pressure to line 61 and oscillate thetracking roll in the opposite direction to move the belt forwardly again.

Figures 4 and 5 illustrate in detail an air eye block according to the present invention. The air eye block comprises a body portion 38a having the central air chamber therein and a wear plate member 38b having the orifice 39 extending therethrough. It will be observed that the wear plate 38b has a generally arcuate upper surface 380 which has its highestpoint at the outlet of the orifice 39. This configuration of the wear plate has been found to allow Bernoullis principle to Work effectively to tend to hold the belt over the orifice. The expected blowing of the belt away from the orifice therefore does not occur. Further, it has been found that with the shape of the wear plate as indicated in Figure 5 that if the edge of the belt accidentally travels past the orifice 39, the belt is still maintained against the aperture in obstructing relation thereto so as to insure operation of the system to move the belt rearwardly out of obstructing relation to the orifice.

It will be readily appreciated that since air pressure such as required in the present system is readily available, the present invention is readily installed for use with existing equipment. Further, it will be observed that the only moving part of the edge sensing system is the mercoid switch so that maintenance ditficulties are kept at a minimum. Also, since air is blown out of the orifice rather than being drawn in, there is no tendency for foreign matter to accumulate in the system. The operation of the system of the present invention has been proved very satisfactory and quite trouble-free.

It will be apparent that many modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a system for effecting continuous lateral oscillation of a web traveling over a tracking roll, the improvement comprising a Web sensing system consisting essentially of a single air discharge member having a chamber therein and disposed for cooperation with one lateral edge only of said web, said discharge member having an air outlet communicating with said chamber for obstruction by said one lateral edge of said web, a fluid conduit connecting with the chamber of said air discharge member, a pressure responsive electric switch in said conduit and actuated by the change in pressure in said chamber resulting from obstruction of said outlet, and means controlled by said switch to oscillate said tracking roll to move said Web away from said outlet upon obstruction thereof by the web, and to move said web toward said '4 outlet upon non-obstruction thereof by said web, said means thereby being operative to continuously laterally oscillate said web.

2. A system for effecting continuous lateral oscillation of a web, comprising means for laterally oscillating said web in opposite lateral directions, a web sensing system consisting essentially of a single air discharge member having a chamber therein and disposed for cooperation with one lateral edge only of said web, said discharge member having an outlet communicating with said chamber for obstruction by said one lateral edge of said web, pressure responsive means communicating with said chamher of said air discharge member and actuated by the change of pressure in said chamber resulting from obstruction of said outlet, and actuating means controlled by said pressure responsive means to actuate said web lateral shifting means to move said web away from said outlet upon obstruction thereof by the web, and to move said web toward said outletupon non-obstruction thereof by said web, said actuating means thereby being operative to continuously laterally oscillate said web.

3. A system for efliecting continuous lateral oscillation of a Web, comprising means for shifting said web selectively in opposite lateral directions, oppositely acting cylinder and piston means operable to actuate said shifting means to shift the web in the respective opposite directions and having one pressure line for supplying pressure thereto to shift the web toward an extreme lateral direction and having a second pressure line for supplying pressure thereto to shift the web away from said extreme lateral direction, a solenoid valve controlling supply of the pressure to said pressure lines and operable in deenergized condition thereof to supply pressure to one of said lines and operable in an energized condition thereof to supply pressure to the other of said lines, edge sensing means cooperable with an edge of the web and actuated by movement of the web to said extreme lateral position, electric means controlled by said edge sensing means and controlling energization of said solenoid valve and operative to energize and deenergize said valve in response to actuation and deactuation of said edge sensing means to condition said solenoid valve. alternately to shift said web away from said extreme position when the web actuates said edge sensing means and to shift said Web toward said extreme position after the edge sensing means has been deactuated, whereby the web continually oscillates toward and away from said extreme position under the control of the edge sensing means.

Hercik Feb. 24, 1942 Czarnecki Mar. 4, 1952 

